Wire bending apparatus



y 22, -1958 s. KUBA ET AL 2,844,171

WIRE BENDING APARA'rus Filed Aug. 12, 1955 2 Sheets-Sheet 1 ,/00 FIG l l "l 16 lNl/EN TORS S. KUBA D. .S. MAGARGEE United States Patent Office Patented July 22, 1958 wnzn BENDING APPARATUS Samuel Kuba, Allentown, and Donald S. Magargee, Center Valley, Pa., assignors to Western Electric Company, Incorporated, New York, N. Y., a corporation of New York I Application August 12, 1955, Serial No. 527,935

Claims. (Cl. 140-71) This invention relates to article forming apparatus particularly apparatus for forming heater coils.

In making heaters for vacuum tubes, the filament wire which, in the present instance, is pure tungsten having a diameter of 0.00337", wound with spacedgroups of like predetermined numbers of turns 'on a wire mandrel of steel or molybdenum. This mandrelated wire is stored on a conventional reel and, heretofore, the heaters were formed therefrom by manually cutting the mandrelated wire into lengths including four coils or groups of turns 'due to the very small size of the material being worked on requiring periods of rest resulting in low production. 1 The object of the invention is an apparatus for cutting and forming articles particularly heater coils for vacuum tubes.

In one embodiment of the invention, a wire of a given length is disposed adjacent an element while a'first former is actuated to bend the wire into a U-shaped form about the element after whicha second former is actuated to cooperate with the first former to bend the legs of .the

U-shaped form of the wire into individual U-shaped forms to complete an M-shaped form of the wire.

More specifically, this embodiment of the invention includes a continuous variable drive for a feed wheel and a one-revolution clutch for connection with a cam shaft. The wire to be formed may be forced by another wheel against the feed wheel to advance a predetermined length of the wire relative to the forming area of the apparatus. The'cam shaft has three cams mounted thereon: one to operate a cutter at the start of each single operating cycle;

a second cam to actuate the first former to accomplish two functions, one the initial forming of the length of wire into a U-shape about a stationary forming element and two, subsequently cause predetermined stretch in the legs of the article to set the form of the article and the third cam to actuate the second former in cooperation with the first former to bend the legs of the initial U-shaped wire into individual U-shapes to form an Meshaped article.

Other objects and advantages will be apparent from the following detailed description when considered in conjunction with the accompanying drawings, wherein:

Fig. 1 is a top plan view of the apparatus;

Fig. 2 is a vertical sectional view taken along the line 2-2 of Fig. 1;

Fig. 3 is a vertical sectional view taken along the line 3-3 of Fig. 2;

Fig. 4 is an enlarged view of the formed article or heater coil; I

Fig. 5 is a schematic illustration of the cutter cam;

Fig. 6 is a schematic illustration of the'first former cam; v Fig. 7 is a schematic illustration of the second former cam;

Fig. 8 is a fragmentary top plan view of the first and second formers and a stationary forming element;

Fig. 9 is a view of the structure shown in Fig. 8 at the end of the forming operation;

Fig. 10 is an enlarged sectional view of a portion of the structure shown inFig. 9, and

Fig. 11. is a fragmentary sectional view taken substantially along the line 11--11 of Fig. 10.

The apparatus shown in Fig. 1 includes a main support 15.having a power means, such as a motor 16 with a variable drive 17, havingan output shaft 18 coupled at 19 to a shaft 20 having a worm 21 mounted thereon. A worm gear 22 driven by the worm 21 is mounted on a shaft 23 journalled in suitable bearings andhaving a drive wheel 24 mounted thereon. An auxiliary wheel 26 mounted on a spindle 27 which is supported by a member 28 disposed between parallel vertically extendingbearing brackets 29. The wheel 26 with its supporting means is spaced from the drive wheel 24 a given distance to allow the mandrelated wire 30 to rest thereon free of the drive wheel 24. A U-shaped lever 31 (Figs. 1 and 2) has its legs positioned to straddle the adjacent bearing bracket 29 and the member 28. The legs of the lever are supported by aligned pivots 32. carried by the adjacent bearingv bracket 29 and provided with elongate apertures 33 to receive pins 34 disposed in alignment with each other and carried by the member 28. A spring 35 urges the lever normally'into its position shown in Figs. 1 and 2. A plate-like member 36 fixed to the connecting portion of the lever serves as a handle portion for manual actuation of the lever to force the wheel 26 upwardly to move the wire 30 into close engagement with the drive wheel 24. The wheels 24 and 26 are'rubber covered to assure gripping engagement with the wire to advance it longitudinally without causing damage to the coil windings on the mandrel. y

The shaft 30 isjjournalled in one portion of a bearing bracket 38 and has a gear 39 mounted thereon. The

gear 39 interengages a gear 40 which is mounted upon a shaft 41 journalled in a suitable bearing in the bearing bracket 38. A cam shaft 42 is journalled in suitable bearings and disposed in axial alignment with the shaft 41 having its left end extending into and supporting its respective portion 43 of a one-revolution clutch 44. The clutch 44 may be of any conventional type, the present clutch being known as a fractional horsepower single revolutionary clutch carrying a pin 46 positioned to engage a stop 47. The stop 47 normally is urged into the position shown by suitable means such as a spring 48.-and is removed momentarily from this position by de-energization of a coil 49 of a solenoid including a core '50 which is connected to the stop 47.

' The cam shaft 42 has earns 51, 52 and 53 mounted thereon. The specific illustrations of these cams shown in Figs. 5, 6 and 7 carry the same reference numerals for the purpose of identification and represent the relative positions of the high portions of these cams starting from the extreme left which represents the idle position of the cam shaft. The cam 51 has a high portion 54 to actuate its cam follower 55. The cam follower is disposed inan aperture of a main frame 56 of the cutting unit, the frame having a dovetailed groove in its undersurface and mounted on a dove-tailed slide 57, the slide being fixedly mounted on the support 15. The cam follower 55 is connected to a cutter 59 normally urged upwardly by a spring 60. A tube 61 mounted in "alignment with-a tube 62 on the opposite side of the feed roller 24 cooperates in determiuing the path of the wire 30 advanced longitudinally from a supply wheel 63, removably supported at 64.

The exit end of the tube 61 is in alignment with an aperture 66 in a portion of the frame 56 which holds the wire and cooperates with the cutter 59 in cutting predetermined lengths from the wire. A lever 67 pivotally mounted at 68 on the support 15 and connected to the main frame or slide 56 of the cutting unit by the aid of a pin 69 may be actuated through its handle 70 to move the cut-ting unit longitudinally of the path of the wire to selectively vary the position of the cut for each length of wire with respect to the forming area of the apparatus. It will be noted that the cam 51 is of sufficient width to allow for the adjustment of the cutting unit relative to the forming area.

' The cam 52 is of the contour illustrated in'Fig. 6 having a starting low portion extending beyond the high portion54 of the cam 51 after which there is a rise to the initial high portion 72 near the end of which there is a momentary higher portion 73 after which there is a decline to the low portion of the cam. A cam follower 75 for the cam 52 is connected directly to a first former 76 shown in detail in Figs. 8 to 11 inclusive. This former has grooves 77 cut inits outer surfaces and grooves 78 cut in its inner surfaces to receive the portions of the wire as they are formed and to maintain these portions in a given plane. The leg portions 79 of the former 76 are parallel with each other, spaced from each other a predetermined distance and of a given thickness depending upon the form to be produced from the mandrelated wire.

In Fig. 1 a table-like structure 81 mounted on the support 15 provides bearing portions to support the cam follower 75 for reciprocable movement. A spring 82 normally urges the cam follower 7-5 against the cam 52 to hold the firstformer 76 in its open or unoperated position. The table 81 has an opening 84 therein adjacent the forming position of the apparatus through which the formed articles as shown in Fig. 4 may drop into a suitable receptacle. Stripping'members 85 (Figs. 8, 9 and .10) are mounted upon the adjacent bearing portion of the table 81 and have their inner ends reduced as at 86 to enter the grooves 77 of the first former 76 to strip the formed article from the former 76.

'A stationary forming element 87 supported by a bracket 88 (Fig. I) mounted on the table 81 extends downwardly from the bracket a distance sufficient to enter the forming area of the apparatus. The successive portions of the wire 30 severed by the cutter 59 res-t upon the table 81 with their central portions adjacent the element 87 as illustrated in Fig. 8.

-A second forming element 90 is bifurcated at 91 to straddle the first former. Both formers have cushions 92 and 93 in the central portions thereof to protect the bends of the wire while being stretched as hereinafter described. The second former 90 is mounted upon a cam follower 94 supported in a suitable manner for reciprocable movement imparted thereto by the cam 53. The cam '53 is of the drum type receiving a roller 95 of the follower 94. The high and low portions of this cam are illustrated in Fig. 7 in comparison with the high and low portions of the cam 52 for the first follower and a cam 51 for the cutter. Before considering the operation of the apparatus, attention is directed to the fact that the motor 16 may be disposed in a circuit which may be closed to cause it to operate continuously while the apparatus is in operation. A circuit, such as illustrated at 98 in Fig. 1, may be provided for the solenoid 49 including a source of electrical energy and a switch 100 which may be closed momentarily to start each operating cycle.

During the operation of the apparatus, the operator actuates thelever 31 (Figs. 1 and 2) to cause the wheel 26 to move the wire 30 into close engagement with the wheel 24, advancing the wire 30-longitudinally until a desired length has been moved into the forming position. H 'desired, a suitable. stop or indicatingmeans may-be employed to assist the operator in-determining the. necessary advancement. of a wire. The advancement of the wire is discontinued by releasing the lever .31 and allowing the spring 351to force the wheel 26' downwardly freeing the wire of the driving force of the wheel 24. At this time, the switch 100 may be closed momentarily to complete the circuit 98 to energize the solenoid 49 causing its core 50 to move against the spring 48 to remove the stop 47 from the clutch pin 46, freeing the clutch "for operation through a single cycle where .it will be stopped and disconnected by the stop 47 having been moved by the spring 48 into its normal position.

During the single cycle engagement of the clutch 44, the camshaft 42 will be rotated causing thecams 51, '52 and 53 to perform their functions in a given order. This may be followed by viewing Figs. 5, 6 and 7 which illustrate the high portion 54 of the cam 51 operating early in the cycle to sever the selected portion-fromthe wire, 10- cating it in the forming position on the table 81 adjacent the stationary forming element 87. Shortly after the portion is cut-from the wire, by viewing Fig. 6, it will be noted that the cam 52 will start moving thefollower 75 toward the forming position causing the bifurcated leading portion of the first former to straddle the stationary forming element to bend the wire portion into a U-shaped form. During the first portion of the movement of the first former 76 relative to the stripping elements 85, the reduced ends 86 of these elements will enter the outer grooves 77 and the first former willstop with the bend of the wire adjacent the cushion 92. The extreme ends ofthe legs of the U-shaped form of-the wire will engage the outside edges of the adjacent end of the second former to assist it in bending the legs of the U-shaped form of the wire into individual U-shaped forms to produce an M-shaped article. By viewing Fig. 7 incomparison with Fig. 6, it will be noted that the second former begins its forming motion after the high portion 72 of the cam 52 has been moved into engagementwith the follower 75. Furthermore, the complete forward forming motion of the second former 90 has been completed andmoved into the position shown in Fig. 10 prior to the higher portion 73 of cam 52 (Fig. 6) moving into engagement with the follower 75. This portion of the cam 52 givesrextramotion to the first former 76 relativeto the stationary forming element 87 and the second former 90 to stretch the bends and the different leg portions of the wire into the cushions 92 and 93 to set the bends and to maintain substantially the M-shape of the article formed of the wire. Further action of the cams to complete the cycle with attention being directed to Figs. 6 and 7 will reveal the return of the second former 90 to its starting or normal position during which time the stationary forming element 87 will act asv an ejector to hold the formed articleagainst movement with the second former 90. The ejecting elements 85 entering the outer grooves 77 will hold the formed article against movement during movement of the first former to its normal or starting position. When the first former is free of the article, the article will have sufi'icient spring back qualities remaining therein to free itself from the stationary element 89 and drop through the aperture-84 into a receptacle. This operation may be repeated at intervals as rapidly as desired, requiring after the initial feeding of the wire from the supply 63 the successive actuation of the lever 31 to advance the-length of wire to the forming position and the closing of the switch momentarily to begin the cycle of operation which is sufficiently rapid and may be varied as desired without damage to the article being formed. Furthermore, the operator may observe the positions of the spaces between the sets of coils on the mandrelated wire to determine the desired position of the cutting unit, making any necessary change in its position through actuation of the lever 67.

It is to be understood that the above describedv arrangements are simply illustrative of the application of the principles of the invention. Numerous other arrangements maybe readily devised bythose skilled in the art whichWill embody the principles of the invention and fall within the spirit and scope thereof.

What is claimed is:

1.'An apparatus for forming wires comprising an ele ment of a given thickness mounted atafixed position and having anoutwardly curved forming edge joining parallel side faces, means to position a wire of a predetermined length ina given path at substantially right angles-to the element with substantially the longitudinal center of the wire disposed adjacent the forming edge, a bifurcated first former with legs of given thicknesses and rounded ends adapted to straddle. the-element, normally positioned away from and in alignment with the element, means operable to move the first former a given distance relative to the element to engage the Wire and bend it into a 'U-shaped form about the forming edge of the element and cause portions of the wire on each side of the bend to be disposed closely adjacent the side faces, a bifurcated second former with legs adapted to straddle the element and the first former, and means operable to move the second former subsequent to said movement of the first former to cause the second former to bend end portions of the wire around the rounded ends of the legs of the first former and to cooperate with the legs of the first former to complete an M-shaped form of the wire.

2. An apparatus for forming wires comprising an element of a given thickness mounted at a fixed position and having an outwardly curved forming edge joining parallel side faces, means to position a wire of a predetermined length in a given path at substantially right angles to the element with substantially the longitudinal center of the wire disposed adjacent the forming edge, a bifurcated first former with legs of given thicknesses and rounded ends adapted to straddle the element, normally positioned away from and in alignment with the element, means operable to move the first former a given distance relative to the element to engage the wire and bend it into a U-shaped form about the forming edge of the element and cause portions of the wire on each side of the .bend to be disposed closely adjacent the side faces, a bifurcated second former with legs adapted to straddle the element and the first former, and means operable tomove the second former subsequent to said movement of the first former to cause the second former to bend end portions of the wire around the rounded'ends of the'legs of the first former and to cooperate with the legs of the first former to complete an M-shaped form of the wire, the means operable to move the first former the given distance being operable also subsequent to the operable means for the second former to move the first former an additional distance to stretch portions of the wire to set the bends in the wire.

3.'An apparatus for forming wires comprising an element'of a given thickness mounted at a fixed position and having an outwardly curved forming edge joining parallel side faces, means to position a wire of a predetermined length in a given path at substantially right angles to the element with substantially the longitudinal center of the wire disposed'adjacent the forming edge, a bifurcated first former with legs of given thicknesses and rounded ends adapted 'to straddle the element, normally positioned away from and in alignment with the element, means operable to move the first former a given distance relative to the element to engage the wire and bend it intoa U-shaped form about the forming edge of the element and'cause portions of the wire on each side of the bend to be disposed closely adjacent the side faces, a bifurcated second former with legs adapted to straddle the element and the first former, and means operable to move the second former subsequent to said movement of the first former to cause the second former to bend end' portions of the wire around the rounded ends of the legs of, the first former and to cooperate with the legs of the first former to complete an M-shaped formof the wire, the first former having parallel inner and outer grooves in the legs thereof angles to the element with substantially the longitudinal center of the wire disposed adjacent the forming edge, a bifurcated first former with legs of given thicknesses and rounded ends adapted to straddle the element, normally positioned away from and in alignment with the element, means operable to move the first former a given distance relative to the element to engage the wire and bend it into a U-shaped form about the forming edge of the element and cause portions of the wire on each side of the bend to be disposed closely adjacent the side faces, a bifurcated second former with legs adapted to straddle the element and the first former, means operable to move the second former subsequent to said movement of the first former to cause the second former to bend end portions of the wire around the rounded ends of the legs of the first former and to cooperate with the legs of the first former to complete an M-shaped form of the wire, the means operable to move the first former the given distance being operable also subsequent to the operable means for the second former to move the first former an additional distance to stretch portions of the wire to set the bends in the wire, and flexible members interposed between the legs of the formers to be engaged by and to cushion the bends in the wire during movement of the first former the additionaldistance to set the bends.

'5. An apparatus for forming wires comprising an element of a given thickness mounted at a fixed position and having an outwardly curved forming edge joining parallel side faces, means to position a Wire of a predetermined lengthin a given path at substantially right angles to the element with substantially the longitudinal center of the wire disposed adjacent the forming edge, a bifurcated first former with legs of given thicknesses and rounded ends adapted to straddle the element, normally positioned away from and in alignment with the element, means operable to move the first former a given distance relative to the element to engage the wire and bend it into a U-shaped form about the formingedge ofthe element and cause portions of the wire on-each side of the bend to be disposed closely adjacent the side faces, a bifurcated second former with legs adapted to straddle the element and the first former,

Y cooperate with the legs of the first former to complete an M-shaped form of the wire, the first former having parallel inner and outer grooves in the legs thereof to receive their respective portions of the wire to maintain them in a given plane, the inner grooves being closed by the faces of the element and the outer grooves being closed by the legs of the second former after forming movements of the formers, the element holding the formed wire during removal of the second former, and means extending into the outer grooves of the legs of the first former to hold the formed wire on the element during removal of the first former.

6. An apparatus for forming lengths of Wire comprising a continuously operable drive means, a wire feeding wheel driven continuously by the drive means and mounted on a fixed position axis with a given plane tangent to the periphery of the wheel, means to' guide a wire in a pathparallel with the plane and normally out of engagement with the wheel, an element of a given thickness mounted at afixed position *at one side ofthe path and having a formingedge joining parallel side faces disposed adjacent the path; formers disposed upon their respective sides of the path, separate actuating means for the formers selectively operated by the drive means to cause actuation of the formers-relative to the element and each other to form a portion of'the wire, an idler roller normally positioned away from the wheel, and means actuable to move the roller towardthe wheel to force a portion of the wire into theplane in close engagement with the wheel to cause the wheel and roller to advance the wire longitudinally through the guide means to position. portions of the wire of predetermined lengths successively in the path adjacent the element and formers.

7. An apparatus for forming lengths of wire comprising a continuously operable drive means, a wire feeding wheel driven continuously by the drive means and'mounted on a fixed position axis with a given plane tangent to the periphery of the wheel, means to guide a wire in a path parallel with the plane and normally out of engagement with the Wheel, an element of a given thickness mounted at a fixed position at one side of the path and having a forming edge joining parallel side faces disposed adjacent the-path, a bifurcated first former with legs of given thickness and rounded ends adapted to straddle the element, normally positioned away from and in alignment with the element, means operable to move the first former a given distance relative to the element to engage the wire and bend it into a U-shaped form about the forming edge of the element and cause portions of the wire on each side of the bend to be disposed closely adjacent 'the'side faces, a bifurcated second former with legs adapted to straddle the element and the first former, means operable to move the second former subsequent-to said movement of the first former to cause the second former to bend end portions of the wire around the rounded ends of the legs of the first former and to cooperate with the legs ofthe first former to complete an M-shaped form of the wire, said operable means for the first and second formers being driven by the drive means, an idler roller normally positioned away from the wheel, and means actuable to move the roller toward the wheel to'force a portion of the wire into the plane in close engagement with the wheel to cause the wheel and roller to advance the wire longitudinally through the guide means to position portions of the wire of predetermined lengths successively in the path adjacent the element and formers.

8. An apparatus for forming lengths of wire comprising a continuously operable drive means, a wire feeding wheel driven continuously by the drive means and mounted on a fixed position axis with a given-plane tangent to the periphery of the wheel, means to guide a wire in a path parallel with the plane and normally out of engagement with the wheel, an element of a given thickness mounted at a fixed position at one side of the path and having a forming edge joining parallelside faces disposed adjacent the path, a bifurcated first former with legs of given thicknesses and rounded ends adapted-to straddle the element, normally positioned away from and in alignment with the element, means operable to move the first former a given distance relative to the element to engage the wire and bend it into a U-shaped form about the forming edge of the element and cause portionsof the wire on each side of the bend to be disposed closely adjacent the side faces, a bifurcated second former with legs adapted to straddle the element and the first former, means operable to move second former subsequent to said movement of the first former to cause the second former to bend end portions of the wire around the rounded ends of the legs of the first former and to cooperate with the legs of the first former to complete an M-shaped form of the wire, said operable'means for the first and second formers being driven by the drive means, an idler roller normally positioned away from the wheel, and means actuable to move the roller toward the-wheel to force a' portion of the wire into the'plane in close engagement with the wheelto cause thewh'e'el and roller to advance the wire longitudinally throughl the guide means to position portions of the Wire of predetermined lengths successively inthe path adjacent the element and formers, the means operable to move the first former the given distance beingoperable also subsequent to the operable means for the second former to move the first former an additional distance to stretch portions of the wire to set the bends in the-wire.

9. An apparatus for forming lengths of wire comprising a continuously operable drive means, a wire feeding wheel driven continuously by the drive means and mounted on a fixed position axis with a given plane tangent to the periphery of the wheel, means to guide a wire in a path parallel with the 'plane and normally out of engagement with the wheel, an element of a given thickness mounted at a fixed position at oneside of the path and having a forming edge joining parallel side faces dis posed adjacent the path, a bifurcated first former with legs of given thicknesses and rounded ends adapted to straddle the element, normally positioned away from and in alignment with the element, means operable to move the first former a given distance relative'to the element to engage the wire and bend it into a U-shaped form about the forming edge of the element and cause portions of the Wire on each side of the bend to be disposed closely adjacent the side faces, a bifurcated second former with legs adapted to straddle 'the element and the first former, means operable to move the second former subsequent to said movement of the first former to cause the second former to bend end portions of the wire around the rounded ends of the legs of the first former and to cooperate with the legs of the first former to complete an M-shaped form of the wire, said operable means for the first and second formers beingdriven by the drive means, an idler roller normally positioned away from the wheel and means actuable to move the roller toward the wheel to force a portion of the wire into the plane in close engagement with the wheel to cause the wheel and roller to advance the wire longitudinally through the guide means to position portions of the wire of predetermined lengths successivelyin the path adjacent the element and formers, the first former having parallel inner and outer grooves in the legs thereof to receive their respective portions of the wire to maintain them in a given plane, the inner grooves being closed by the faces of the element and the outer-grooves being closed by the legs of the second former after forming, movements of the formers.

10. An apparatus for forming lengths of wire comprising a continuously operable drive means, a Wire feeding wheel driven continuously by the drive means and mounted'on a fixed position axis with a given plane tangent to the periphery of the-wheel, means to guide a wire in a path parallel with the plane and normally out of engagement with the wheel, an element of a given thickness mounted at a fixed position at one side of the path and having a forming edge joining parallel side faces disposed adjacent the path, a bifurcated first former with legs of given thicknesses and rounded ends adapted'to straddle the element, normally positioned away from and in alignment with the element, means operable to move the first former a given distance relative tothe element .to engage the wire and bend it into a U-shaped'formabout the forming edge of the element and cause portions of the wire on'each side of the bend to be disposed closely adjacent the side faces, a bifurcated second former with legsadapted to straddle the element and thefirst former, means operable to move-the second former subsequent'to said movement of the first former to cause the second former to bend end portions of the Wire around the rounded ends of the legs of the first former and to cooperate with the legs of the first former tocomplete' an M-shapedform of the wire, said'operable meansfor the first and second formers being driven by the drive means, an idler roller normally positioned away from the wheel, and means actuable to move the roller toward the wheel to force a portion of the wire into the plane in close engagement with the wheel to cause the wheel and roller to ad- J vance the wire longitudinally through the guide means to position portions of the wire of predetermined lengths successively in the path adjacent the element and formers,

and flexible members interposed between the legs of the formers to be engaged by and to cushion the bends in the wire during movement of the first former the additional distance to set the bends.

References Cited in the file of this patent UNITED STATES PATENTS Thompson May 19, 1885 Einfeldt Dec. 24, 1901 Merritt June 13, 1916 Hoffman Sept. 6, 1927 Myers Aug. 30, 1949 Albrecht Apr. 22, 1952 Klemm Nov. 17, 1953 

